Conventional circuit breakers are usually placed in operative position either singly or in banks of side-by-side units. These units can contain a handle which protrudes from the circuit breaker or a plurality of switches which are provided within the casing. When a number of such circuit breakers are in a group, as they conventionally are, it is often difficult to ascertain which circuit breaker has its handle or switch in a blown position, particularly since most circuit breakers are in cellars or in similar dimly-lit locations. In addition, even when the circuit breakers are in brightly-lit areas, it is often difficult to determine the particular circuit breaker which has blown. This, of course, is important since when an overload occurs and a circuit is blown, it must be found and corrected before resetting the circuit breaker, thereby considerably reducing the risk of life and material losses.
The prior art is replete with various devices containing a circuit breaker associated with a visual or aural indicator which positively shows which one of several circuit breakers has blown. One such device is described in U.S. Pat. No. 4,056,816 issued to Raul Guim, showing an illuminated circuit breaker utilizing a light-emitting diode to indicate when the circuit breaker has blown. This diode is provided in a circuit parallel to the main switch of the circuit breaker and when this switch is tripped due to the sensing of an overload condition, the light-emitting diode is connected into the circuit and begins to illuminate and remain lit until the problem is rectified. However, this patent does not disclose any means for sensing the presence of an overload condition other than by providing an indicating means directly connected into the circuit breaker circuit. Furthermore, the patent to Guim does not indicate the presence of any means for setting the alarm other than be directly connecting the circuit.
U.S. Pat. Nos. 2,460,758 issued to Lawson; 3,562,733 issued to Murphy et al; 3,683,350 issued to Shedenheim; 3,816,827 issued to Lynn, Jr. and 4,358,810 issued to Wafer et al all disclose circuit breakers having an alarm or other indication that a circuit has blown. For example, the patent to Lawson shows a lockout and alarm device for circuit breakers whereby the movement of a magnet causes a tripping alarm to rotate and thereby allow a movable contact to engage a stationary contact, thereby completing an alarm circuit whereby a lamp lights or a bell rings. Similarly, the patents to Murphy et al, Shedenheim, Lynn, Jr. and Wafer et al are provided with alarm circuits which are provided in a circuit which is physically connected to either a device for sensing that an overload has occurred or the device which is tripped when the overload is sensed. Additionally, although the patents to Lawson and Murphy et al also describe a device for manually setting the alarm circuit, neither of these patents discusses such a setting device which is provided between the circuit breaker door and the door frame.